New techniques for determining important cardiac parameters with ultrasound are being developed. Central to this effort is a new method of locating the position and orientation of the sound beam or sector scan with respect to a coordinated system. This method does not require any mechanical arms and thus provides for significantly improved freedom of motion by the sonographer. Studies to date have demonstrated the high accuracy of this system. In addition, three-dimensional imaging of models has been carried out by combining the locator system with a real-time scanner. Programs are available which permit the operator to view the reconstructed image from any desired location. In addition, volume calculations can be performed automatically.